scholarly journals Optical Counterparts to Galaxies in the Cen A Group Discovered by HIPASS

1999 ◽  
Vol 16 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Patricia M. Knezek
Keyword(s):  
Surface Brightness ◽  
Survey Area ◽  
Late Type ◽  
New Members ◽  
Low Surface Brightness ◽  
Survey Technique ◽  
Group Members ◽  
The Subject ◽  
Centaurus A

AbstractWe have completed a 21-cm survey of a 600 square degree region of the Centaurus A group of galaxies at a redshift of ∼500 km s−1 as part of a larger survey of the entire southern sky. This group of galaxies was recently the subject of a separate and thorough optical survey (Côté et al. 1997), and thus presented an ideal comparison for us to test the survey performance. We have identified 10 new group members to add to the 21 already known in our survey area. Six of the new members are previously uncatalogued galaxies, while four were catalogued but assumed not to be group members. Including the seven known members outside of our survey area, this brings the total known number of Cen A members to 38. All of the new HI detections have optical counterparts, most being intrinsically very faint (MB > –13·0), late-type low surface brightness dwarfs. Most of the new members have HI masses only a few times our survey limit of 107M☉ at an assumed distance for the group of 3·5 Mpc, and are extremely gas-rich, with a median MHI/LB > 1. Our limiting HI sensitivity was actually slightly worse than the HI follow-up observations of the Côté et al. optical survey, yet we have already increased the known number of group members by 50% using an HIsurvey technique. While we have increased the known number of members by ∼50%, these new members contribute <4% to its light.

scholarly journals An optical and H I study of late-type low surface brightness galaxies

1982 ◽  
Vol 200 (2) ◽  
pp. 325-346 ◽  
Author(s):  
A. J. Longmore ◽  
T. G. Hawarden ◽  
W. M. Goss ◽  
U. Mebold ◽  
B. L. Webster
Keyword(s):  
Surface Brightness ◽  
Late Type ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

scholarly journals Systematic search for tidal features around nearby galaxies

2018 ◽  
Vol 614 ◽  
pp. A143 ◽  
Author(s):  
Gustavo Morales ◽  
David Martínez-Delgado ◽  
Eva K. Grebel ◽  
Andrew P. Cooper ◽  
Behnam Javanmardi ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Galaxy Formation ◽  
Surface Brightness ◽  
Stellar Structure ◽  
Wide Field ◽  
Low Surface Brightness ◽  
Nearby Galaxies ◽  
Tidal Streams ◽  
Galaxy Population

Context. In hierarchical models of galaxy formation, stellar tidal streams are expected around most, if not all, galaxies. Although these features may provide useful diagnostics of the Λ CDM model, their observational properties remain poorly constrained because they are challenging to detect and interpret and have been studied in detail for only a sparse sampling of galaxy population. More quantitative, systematic approaches are required. We advocate statistical analysis of the counts and properties of such features in archival wide-field imaging surveys for a direct comparison against results from numerical simulations. Aims. We aim to study systematically the frequency of occurrence and other observational properties of tidal features around nearby galaxies. The sample we construct will act as a foundational dataset for statistical comparison with cosmological models of galaxy formation. Methods. Our approach is based on a visual classification of diffuse features around a volume-limited sample of nearby galaxies, using a post-processing of Sloan Digital Syk Survey (SDSS) imaging optimized for the detection of stellar structure with low surface brightness. Results. At a limiting surface brightness of 28 mag arcsec−2, 14% of the galaxies in our sample exhibit evidence of diffuse features likely to have arisen from minor merging events. Our technique recovers all previously known streams in our sample and yields a number of new candidates. Consistent with previous studies, coherent arc-like features and shells are the most common type of tidal structures found in this study. We conclude that although some detections are ambiguous and could be corroborated or refuted with deeper imaging, our technique provides a reliable foundation for the statistical analysis of diffuse circumgalactic features in wide-area imaging surveys, and for the identification of targets for follow-up studies.

scholarly journals Detections of CO in Late-Type, Low Surface Brightness Spiral Galaxies

2005 ◽  
Vol 129 (4) ◽  
pp. 1849-1862 ◽  
Author(s):  
Lynn D. Matthews ◽  
Yu Gao ◽  
Juan M. Uson ◽  
Françoise Combes
Keyword(s):  
Surface Brightness ◽  
Spiral Galaxies ◽  
Late Type ◽  
Low Surface Brightness

scholarly journals The Abell 35-Type Planetary Nuclei

1993 ◽  
Vol 155 ◽  
pp. 397-397 ◽  
Author(s):  
Howard E. Bond ◽  
Robin Ciardullo ◽  
Michael G. Meakes
Keyword(s):  
Surface Brightness ◽  
Late Type ◽  
Low Surface Brightness ◽  
Low Amplitude

The nuclei of the low-surface-brightness PNe A 35, LoTr 1, and LoTr 5 are binaries containing rapidly rotating late-type subgiants or giants and extremely hot (Teff ≳ 100,000 K) companions detected by the IUE satellite. All three objects show low-amplitude, periodic photometric variations in the optical band (with periods of 0.76 or 3.3, 6.6, and 5.9 days, respectively).

scholarly journals Historical Introduction

1999 ◽  
Vol 171 ◽  
pp. 3-8
Author(s):  
K.C. Freeman
Keyword(s):  
Angular Momentum ◽  
Surface Brightness ◽  
Brightness Distribution ◽  
Clusters Of Galaxies ◽  
Low Surface Brightness ◽  
The Subject ◽  
Potential Impact ◽  
Fisher Relation ◽  
Low Surface Brightness Galaxies ◽  
Present View

AbstractOur ideas about the surface brightness distribution of galaxies has changed greatly since 1970. I contrast the view at that time with our present view of the subject, and then briefly discuss some topics in the studies of Low Surface Brightness Galaxies (LSBG) that I think are particularly interesting: the Tully-Fisher relation, LSBG as systems of high angular momentum, LSBG in clusters of galaxies, and the potential impact of the HIPASS survey.

scholarly journals The dust distribution in late-type low surface brightness disks

2011 ◽  
Vol 7 (S284) ◽  
pp. 101-103
Author(s):  
John MacLachlan ◽  
Lynn Matthews ◽  
Kenny Wood ◽  
Jay Gallagher
Keyword(s):  
Surface Brightness ◽  
High Surface ◽  
Stellar Disk ◽  
Disk Galaxies ◽  
Late Type ◽  
Vertical Scale ◽  
Low Surface Brightness ◽  
Multi Wavelength ◽  
Low Mass ◽  
Dust Distribution

AbstractLate-type low surface brightness (LSB) disk galaxies are common in the local universe and appear dynamically and chemically under evolved compared to their high surface brightness (HSB) counterparts. We have utilized multi-wavelength imaging and photometry of three edge-on, low-mass LSB disk galaxies to investigate the dust distribution in such systems. Through the use of Monte Carlo radiation transfer models to interpret the data, we find that the dust disk appears to have a vertical scale height similar to the stellar disk. This is in contrast to previous findings from HSB galaxies, where the dust is believed to be more concentrated in the galactic mid-plane. We believe the change in the relative scale heights of the dust and stellar disks is likely associated with the increased stability of the ISM against vertical collapse and the thin nature of the stellar disks.

scholarly journals The Frequency of Anomalously Red Galaxies in SDSS Clusters

2014 ◽  
Vol 31 ◽  
Author(s):  
O. Shearman ◽  
K. A. Pimbblet
Keyword(s):  
Surface Brightness ◽  
Dust Content ◽  
Early Type ◽  
Late Type ◽  
Cluster Membership ◽  
Cluster Galaxies ◽  
Low Surface Brightness ◽  
Magnitude Diagram ◽  
Red Galaxies ◽  
Red Sequence

AbstractWe present a systematic photometric search for spectroscopically confirmed anomalously red galaxies members of 748 low redshift clusters between 0.03 z 0.17 from the SDSS-C4 cluster catalogue (Miller et al. 2005). For each cluster we spectroscopically determine cluster membership, construct a colour-magnitude diagram and fit the red sequence using a robust bi-weight fit. We define an “anomalously red galaxy” as having a (g - r) colour of greater than 3σ redward of the fitted cluster colour-magnitude relation. We find that of 7485 galaxies at r ≤ 17.77 in (g - r), 7 galaxies are anomalously red – 0.0935 per cent of all galaxies in our sample. We show that two of the red outliers are caused by red contamination from nearby sources and are therefore not intrinsically anomalous red. However, 5 have no underlying cause to be so red and we speculate that they may have a high internal dust content. These intrinsically red galaxies are rare – comprising no more than 0.0668 per cent of all cluster galaxies. Most are morphologically early type galaxies, with a few probable late type galaxies that are viewed edge-on and one low surface brightness late type. One of our anomalously red galaxies appears to be a dust-shrouded starburst and we speculate that this may be a unique galaxy amoungst this galaxy set.

scholarly journals The Dynamical Evolution of Centaurus A

1996 ◽  
Vol 171 ◽  
pp. 463-463
Author(s):  
S.G. Vine ◽  
R.C. Thomson
Keyword(s):  
Simulation Model ◽  
Spiral Galaxy ◽  
Surface Brightness ◽  
Dynamical Evolution ◽  
Interacting Galaxies ◽  
Dust Lane ◽  
Preliminary Results ◽  
Axis Of Rotation ◽  
Low Surface Brightness ◽  
Centaurus A

Centaurus A (NGC 5128) is a nearby Giant Elliptical (3.5Mpc, 1012 Solar Masses). It has a prominent dust-lane which has an axis of rotation orientated differently from that of the underlying galaxy. Close to it are two galaxies: NGC 5237 – a dwarf elliptical, and Fourcade-Figueroa – a low surface brightness irregular. We are investigating whether these three objects are the resulting components of a grazing interaction between a Giant Elliptical and a less massive spiral galaxy. We have conducted n-body simulations, modelling all components of the two original interacting galaxies. Preliminary results show that Cen A, its dust-lane, and NGC 5237 are consistent with this simulation model. Centaurus A exhibits many other features which are also indicative of a past interaction.

scholarly journals A Survey for Low Surface Brightness Dwarf Galaxies Around M31

1999 ◽  
Vol 171 ◽  
pp. 111-119 ◽  
Author(s):  
Taft E. Armandroff ◽  
James E. Davies ◽  
George H. Jacoby
Keyword(s):  
Surface Brightness ◽  
Dwarf Galaxies ◽  
Digital Filtering ◽  
Low Surface Brightness ◽  
Filtering Technique

AbstractBy applying a digital filtering technique to 1550 deg2 of the POSS-II in the vicinity of M31, we found two previously unidentified very low surface brightness dwarf galaxies which we designate And V and VI. Follow-up imaging with the KPNO 4-m telescope resolved these into stars easily. The V- and I- band images of And V indicate a distance similar to that of M31, and <[Fe/H]> ~ −1.5. All evidence strongly supports its classification as a dwarf spheroidal companion to M31. Data for And VI are being analyzed, but preliminary indications support a similar conclusion. Our search for more dwarfs, including follow-up observations of numerous candidates found via digital filtering, is incomplete; thus, further identifications may be forthcoming.

A Survey for Low Surface Brightness Galaxies around M31. II. The Newly Discovered Dwarf Andromeda VI

1999 ◽  
Vol 118 (3) ◽  
pp. 1220-1229 ◽  
Author(s):  
Taft E. Armandroff ◽  
George H. Jacoby ◽  
James E. Davies
Keyword(s):  
Surface Brightness ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies
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